The field of the invention relates generally to the design and manufacture of electromagnetic components and related design and fabrication methods, and more particularly to the manufacture of electromagnetic actuators.
Electrical devices, including but not necessarily limited to relays, contactors, switchgear and circuit breaker devices sometimes employ electromagnetic actuators to disconnect or break a circuit path in an electrical power distribution system when electrical overcurrent or overload conditions are detected.
Switchgears and relays, for example, generally include two sets of contacts, one of them typically being movable and the other being stationary. The movable contact is moved by electromagnetic actuators including a coil wound around a core. When current flows through the coil (i.e., when the electromagnetic actuator is energized), a magnetic field is produced in the core, which displaces an actuator element (e.g. a plunger) in the assembly. The plunger in turn moves the movable contact of the switchgear or relay towards the fixed or stationary contact. The force developed by the electromagnet holds the movable and stationary contacts together. When the electromagnetic actuator coil is de-energized (i.e., when current ceases to flow through the coil), gravity or a bias element such as a spring returns the plunger to its initial position and opens the contacts. This operation can be reversed by mechanical design such that when the plunger moves during actuation the contacts will open rather than close.
Solenoid valves are used in fluid power, pneumatic and hydraulic systems, to control cylinders, fluid power motors or larger industrial valves. They generally also include a plunger adapted to move in a desired way to open and close gates of the valve and allow passage of fluids. Movement of the plunger happens in presence of a magnetic field generated in the core of an electromagnetic actuator when the coil of electromagnetic actuator is energized.
Electromagnetic manufacturers are facing an increased demand to reduce the size and power loss of electrical and or hydraulic systems that are used is variety of applications, including but not limited to complex industrial applications, aviation applications, high voltage switchgear and electrical power distribution systems, and vehicle applications such as power door locks or central locking applications. While the demand for increasingly smaller and energy efficient electrical and/or hydraulic systems is growing, electromagnetic actuator manufacturers face practical challenges in reducing the size and power loss of electromagnetic actuators to meet the desires of the marketplace. By decreasing the size and power loss of the actuators in electrical and hydraulic systems, not only the size and energy efficiency of devices employing such actuators can be reduced, but also the performance and capabilities of electrical and/or hydraulic systems can be enhanced. Improvements are therefore desired.